Generally, designed for longer term sitting, chairs can be uncomfortable. Sedentary working environments promote little to no engagement of core muscles while sitting and can result in debilitating health problems. Engaging the core muscles while sitting can improve core strength and posture, and targeting key muscle groups such as the gluteal and piriformis muscles further enhance comfort, especially around the sciatic nerve.
Both U.S. Pat. Nos. 5,590,930 and 5,921,628 portray active seats that utilize a mechanism in the base promoting the use of core muscles while sitting. This mechanism allows for tilting in all directions about an axis, and also includes a mechanism which returns the seat to its original position. However, the devices described in these patents do not provide sufficient adjustments to better suit different body types.
Beyond activating core muscles, targeting key muscle groups are an important method of promoting circulation. U.S. Pat. No. 8,372,111 describes methods in which to activate the piriformis muscle through active and passive massaging. However, there is no suggestion or teaching as to integration of a mechanism into a seat having similar functionality, nor is there any discussion as to how any such functionality would be achieved by user operation.
U.S. Patent Application Publication 2011/0095586 describes a tilting mechanism that allows for full rotation about a single axis, along with tilting in all directions. There exists a need to fix the rotational axis of the chair to be able to stretch and engage back muscles while in the seated position, and with no way of fixing the rotational axis, the device of this publication is limited only to activating muscles in a user's core.
U.S. Patent Application Publication 2013/0113249 combines a chair with electronic sensors, data transfer capabilities, and a power source, but only uses these capabilities to suggest proper use of the seat.